STUDIES FOR ESTIMATING THE BIOLOGIC BEHAVIOR AND PROGNOSIS OF PARAGANGLIOMAS IN THE HEAD AND NECK

Despite a large number of histopathologic and immunohistochemical stud ies, the biologic behavior and prognosis of paragangliomas (glomus tum ors) of the head and neck still remain uncertain. In the present study 36 specimens from 32 patients who underwent surgery for a paraganglio ma were examined. The examinations included routine histology, quantit ative DNA analysis based on image cytometry, immunohistochemical detec tion of the proliferating cell nuclear antigen (PCNA) along with visua lization of nucleolar organizer regions (AgNOR). According to LeCompte , the paragangliomas were histologically divided into three subcategor ies: 16 patients had a paragangliomatous tumor, 14 patients had an ade nomatous tumor, and 6 patients had an angiomatous tumor. Quantitative DNA analysis revealed three categories of tumors with characteristical DNA pattern: DNA type I tumors were pure diploid, DNA type II tumors had stemlines at 2c and 4c and were therefore recognized as diploid-te traploid. Aneuploid cells were not apparent in these two groups. DNA t ype III tumors had stemline ploidies exceeding 2c and 4c. Aneuploid ce lls were present in all of these tumors. The biologic behavior of thes e lesions therefore must be recognized as suspicious. DNA type III tum ors and adenomatous tumors showed the highest values for the PCNA scor es, indicating a higher proliferation rate and a more rapid growth pat tern in these lesions. Twenty patients could be followed over a period of up to 110 months. Five of these patients developed a recurrent tum or. All of them had DNA type III tumors. The DNA indices showed signif icantly higher values in the recurrent tumor group. The 2c deviation i ndex (DI) and the entropy value had the highest prognostic significanc e. No correlation to clinical follow-up was found for the AgNOR score. Based on these results, prognostic indices for paragangliomas were de veloped: patients with a tumor having a 2c DI exceeding 2.0, entropy v alue of more than 4.0, 5c exceeding rate more than 8.0, and a PCNA sco re more than 20.0% can be recognized as being a high-risk for developi ng recurrent disease.